Secondary measures will include the positive and negative syndrome scale (PANSS) and other movement disorder scales (Simpson-Angus Rating Scales) for acute extrapyramidal symptoms (EPS), and the Barnes Akathisia Rating Scale (BARS). Global impressions of efficacy and tolerability by the clinician (CGI) and by the patients (PGI) will be recorded at all study visits after the commencement of treatment. To assess potential cognitive changes that may occur in conjunction with TD changes, a battery of neuropsychological tests will be carried out at baseline and endpoint (see Appendix II). To assess the relationship with primary negative symptoms such as the deficit syndrome, the total and sub-scales of the Positive and Negative Syndrome Scale will be evaluated.